Hydraulic lift



Oct- 30, 1962 A. SHOTMEYER 3,061,044

HYDRAULIC LIFT Filed May 16, 1962 FIG.I so

REVERSIBLE ELECTRIC MOTOR POSITIVE DISPLACEMENT PUMP HIS ATTORNEY O O O80 //6 O\\ /20 /f ,so T O 70, 64 \/32 O n /f' L: f/ o\\ l es' o o\ O lol OI O /l l' \O Q A. \Q 9/ e "Q54 Q O O f \Q\ ,9 INVENToR Q ALBRTSHOTMEYER O o O O BY United States This invention relates to hydrauliclifts, and more specically to novel service station hydraulic liftinstallations.

Heretofore it has been customary to construct service station hydrauliclifts as permanent constructions which could not readily be moved fromplace to place. The moving of such a lift from one place to another is amajor operation, requiring the excavation of the lift, which is usuallyembedded in the ground, the excavation of a hole at the new site and thereinstallation of the lift at the new site. This calls for considerablelabor, including preparing orms for concrete and pouring of concrete.

It is an object of this invention to provide a novel hydraulic liftwhich can readily and easily be installed withina pit and which can bereadily and easily removed therefrom for repair, servicing, or forremoval to a different location, by unskilled labor.

It is a further object to provide a novel self-contained hydraulic liftunit, including novel construction features, capable of being completelyassembled at a manufacturing plant, and shipped to the point of usewhere it can be readily placed in operative position in a minimum oftime and without interfering with other service station operations.

It is a still further object to provide a novel self-contained hydrauliclift in which all of the component elements are housed within a tankwhich can be suspended within a relatively shallow pit in the iioor of aservice station, and which can readily be moved and suspended in anothersimilar pit when desired.

The attainment of the above objects and other objects and advantageswill become evident from a consideration of the following specificationand the accompanying drawings, in which:

FIG. 1 is a sectional view of a preferred form of the invention; and

FIG. 2 is a plan view of the hydraulic lift shown in FIG. l.

Referring to the accompanying drawings, in which corresponding elementsin the several iigures are designated by the same reference character,the numeral designates the oor of a service station which may have oneor more pits 12 located at convenient points. The pits may be circularor rectangular in cross section, having side Walls 14 lined with cinderor concrete blocks 15, and a bottom wall 16. The pit 12 is relativelyshallow, for example, about 4 feet deep, and the bottom wall may beearth or lined with concrete and provided wtih a suitable drain 17ifdesired., One side wall 14 carries a conventional electric outlet 18which is in a circuit including a conventional two-way switch, notshown.

`A hydraulic lift, designated in its entirety by the numeral 2t), isadapted to be suspended within the pit 12 wit-h the side Wall and bottomwall of the lift in spaced relation with the side walls and the bottomwall, respectively, of the pit. The hydraulic lift 20 comprises acylindrical tank 22 having a side wall 24 and a bottom wall 26, beingmade of heavy gauge steel to support the hydraulic jack therein. Theupper end of the tank 22 is open, and is adapted to be covered by arectangular cover plate 28 to which the tank is attached by a series ofbolts and nuts 32 passing through registering openings in a ange on theupper end of the tank and in the cover plate 28. The cover plate 28 ismade of heavy gauge steel, and may be reinforced by ribs and the like,not shown, to support atent G fice the weight of the tank, the jack anda load thereon. While the tank 22 is shown in the drawings as beingcircular in cross section and the cove'r plate is shown as beingrectangular inA outline, it is evident that the tank may assume otherforms in cross section, such as rectangular or elliptical, and likewisethe cover plate may be made in other shapes.

A hydraulic jack 34 is mounted within the tank 22, being supported bythe bottom wall 26. The jack 34 comprises a cylinder 36, the lower endof which is closed by a bottom plate 3S which may be secured to thebottom wall 26 of the tank by any suitable means, such as by welding 4u.Telescopically disposed within the cylinder 36 are a plurality of hollowsectional pistons 42, 44 and 46, each piston having a lower externalflange 48, Sti and 52, respectively, retaining the piston in concentricrelation with the cylinder 36 and with the interior of another pist0n,the anges 48, 50 and 52 forming pressure surfaces for the piston 42, 44and 46, respectively, the hollow interior wall of the pistons 42 and 44serving as cylinders for the pistons 44 and 46, respectively. The upperend of the piston 46 carries a plate 54 projecting beyond the exteriorwall of the piston to be engaged by the upper ends of the pistons 42 and44. The upper end of the hydraulic jack 34 includes conventional means,not shown, to guide the pistons within their respective cylinders and tolimit the upward movement of the pistons. A conventional H-frame 60 ismounted on the plate 54. The upper end of the cylinder 36 is providedwith a flange 62 which is attached to the cover plate 28 by a series ofbolts and nuts 64. A central opening `66 in the cover plate 28 providesa guide for the piston 42.

A reversible pump and motor unit 68 is mounted within the tank 22 by aange 70 bolted to the cover plate 28, the unit 68 being suspended in thetank through an opening in the cover plate. An inlet conduit 72 isconnected at one end with the unit 68, the other end having a strainer74 disposed adjacent the bottom wall 26 of the tank 22. A second conduit76 is connected at one end with the unit 68 and at its other end to theinterior of the cylinder 36 below the pistons 42, 44 and 46. Anelectrical conductor 78 extends from the motor of the unit 68 through anopening in the wall 24 of the tank 22, having a plug on the end thereofwhich is received within the electrical outlet 1S to supply electricalcurrent to the motor.

As seen in FIG. 1, the dimensions of the cover plate 28 are greater thanthe transverse dimensions of the pit 12 whereby the peripheral edges ofthe cover plate overlap the vfloor 1t) surrounding the pit. A series ofspaced apertures 80 around the periphery are adapted to receive screws82 engaging threaded bores in the floor to secure the cover plate 28 andthereby the hydraulic lift in position. Since the transverse dimensions`and depth of the tank 22 are less than the transverse dimensions anddepth of the pit, respectively, the cover plate 28 suspends the tank 22and its contents in spaced relation with reference to the side walls andbottom wall of the pit.

The pump of the reversible pump and motor unit 68 is of the positivedisplacement type, such as a gear pump or rotary piston pump and thelike, whereby rotation of the pump in one direction causes a ow ofliquid under pressure in one direction through the conduits 72 and 76,and rotation of the pump in the other direction causes a ow of liquid inthe other direction through the corsi,- duits. The electric motor of theunit 68 is reversible and is drivingly connected with the pump. Aremotely positioned switch, not shown, is operative to stop and tochange the direction or rotation of the electric motor.

A quantity of liquid, such as oil, is placed within the Patented Oct.30, 1962` tank 22. With the jack 34 in its retracted position, the

reversing switch, not shown, is operated to cause rotation.

' the liquid and a retraction of the jack and H-frame.

The entire hydraulic lift 2G may be completely assembled at themanufacturing plant, and the liquid within the tank may either be placedin the tank at the time of manufacture or just before the lift is placedin the pit. One or a number of pits 12 can be constructed at a servicestation, at desirable locations, and a hydraulic lift can be installedin each pit, or, if desired, a hydraulic lift can be moved from one pitto another, as needed, and the pit, when not occupied by a lift, can becovered. The entire hydraulic lift assembly can be easily installed andremoved when desired, and can be readily disassembled for maintenanceand repair. Because of the sectional piston construction, a relativelyshallow pit can be provided, thus reducing construction costs.

The conduit 76 can be made of flexible material, such as braided hoseand the like, and of suiiicient length to permit the removal of themotor and pump unit 68 from the cover plate 28 without disconnecting theconduit from the lower end of the cylinder 36.

Having fully described my invention, it is to be understood that I donot wish to be limited to the details set forth herein, but that variouschanges may be made in the details and proportions without departingfrom the principles of the invention or from the scope of the annexedclaims.

I claim:

1. In a service station installation having a door, means providing apit in said floor having a bottom wall and side walls, and a hydrauliclift within said pit, said hydraulic lift comprising a tank having atleast one side wall and a bottom wall, the depth and transversedimensions of said tank being less than the corresponding dimensions ofsaid pit, a hydraulic jack supported on the bottom wall of said tank, apump, conduit'means connecting said pump with the bottom of said tankand with said jack, and means supporting said tank Within said pit inspaced relation with the walls of said pit.

2. In a service station installation as deined in claim 1, wherein saidjack comprises a plurality of telescopically related pistons.

3. In a service station installation as defined in claim 1, wherein saidpump is of the positive displacement type and reversible power meansdrivingly connected with said pump.

4. In a service station installation as defined in claimY 1, whereinsaid pump is of the positive displacement type and is mounted withinsaid tank, and reversible power means drivingly connected with saidpump.

,5. In a service station installation as defined claim 1,

wherein said means supporting said tank comprises a tank cover plate,means to attach the tank to said cover plate, said cover plate havingdimension greater than the transverse dimensions of said pit, wherebythe peripheral edge of said cover plate is supported by the floorsurrounding the pit and said tank is suspended within said pit, saidcover plate including an opening through which said jack is adapted toextend.

' 6; In a service station installation as defined in claim 1, whereinsaid means supporting said tank comprises a tank cover plate, means toattach the tank to said cover plate, said cover plate having dimensionsgreater than the .transverse dimensions of said pit, whereby theperipheral edge of the cover plate is supported by the floor surroundingthe pit and said tank is suspended within said pit, said cover plateincluding an opening through which said jack is adapted to extend, andwherein said pump is of the positive displacement type, reversible powermeans drivingly connected with said pump, and means attaching said pumpand power means to said cover plate.

7. A hydraulic lift for installation within a service station pit,comprising: a tank having at least one side wall and a bottom wall; acover plate having greater dimension than the transverse dimension ofsaid tan-kymeans attaching said tank to said cover plate wherebyperipheral portions of said cover plate project beyond the side wall ofsaid tank to engage the oor about a pit to suspend said tank within saidpit; a hydraulic jack within said tank and supported by said bottomwall, said cover plate including an opening through which said jack isadapted to extend; and pump meansV having iluid connections with thespace within said tank and with said hydraulic jack.

8. A hydraulic lift as definedY in claim 7, in which said jack comprisesa plurality of telescopically related pistons.

9. A hydraulic lift as defined in claim 7, in which said pump is of thepositiveV displacement type, and reversible power means drivinglyconnected with Said pump.

10. A hydraulic lift as defined in claim 7, in which said pump is of thepositive displacement type, reversible power means drivingly connectedwith said pump, and means attaching said pump and power means to saidcover plate.

References Cited in the le of this patent UNITED STATES PATENTS 986,888Zimmerman Mar. 14, 1911 1,518,780 Erickson Dec` 9, 1924 1,567,203Steinkamper Dec. 29, 1925 1,720,980 Trapp July 16, 1929 1,784,554Stukenborg Dec. 9, 1930 1,985,510 Lunati Dec. 25, 1934 2,915,357 WeaverSept. 24, 1935 2,498,304 Sommer Feb. 2,1, 1950 2,711,632 Ellis June 2S,1955 FOREIGN PATENTS 391,131 Great Britain Apr. 18, 1933 1,128,864France Aug. 27, 1956

